Table 3.

Deregulated expression of growth factor and IGF-I pathway genes. Deregulated expression of growth factor genes underlines erbB4-KOD hearts by the upregulation of Egf, Hb-egf, Ptn, Post and downregulation of Fgf1 and IgfI. Comparative expression of genes related to the IGF-I pathway exhibits an extended downregulation in erbB4-KOD relative to KO hearts. Abbreviations: phosphatidylinositol 3-hydroxi kinase (PI3′-K); murine thymoma viral oncogene homolog 2 serine/threonine protein kinase (Akt2). Statistically significant data correspond to fold change ratios at FDR < 10, ns: not significant.

Gene	Genebank	ErbB4-KO		WTD		ErbB4-KOD
		ratio	FDR	ratio	FDR	ratio	FDR
Growth factors
Fibroblast growth factor 1 (Fgf1)	AA261582	0.6	4.9	1.0	ns	0.7	14
Glial cell derived neurotrophic factor (Gdnf)	W45748	1.3	ns	1.8	5.3	1.3	ns
Gndf receptor 3 (Gdnra3)	AA050083	2.0	2.0	1.1	ns	1.6	2.0
Epidermal growth factor (Egf)	AI326499	0.6	5.0	1.3	ns	4.6	0.6
Egf-fibulin-like extracellular matrix (Efemp)	AI156278	0.7	9.5	0.7	ns	6.4	8.9
Heparin binding-Egf (Hbegf)	AI595201	1.4	ns	4.6	0.6	4.5	9.4
Pleiotrophin (Ptn)	AI047160	1.0	ns	2.6	ns	4.5	0.5
Secreted frizzled-related (Srfp)	AI019575	1.0	ns	1.2	ns	2.0	0.7
Periostin, osteoblastic factor (Postn)	W81878	1.5	3.5	0.9	ns	1.5	1.5
Insulin-like growth factor-I (Igf1)	AI604642	0.7	ns	1.1	ns	0.35	0.2
IGF-I signaling
Insulin-like growth factor-I (Igf1)	AA822429	0.75	16	1.1	ns	0.52	0.2
Insulin-like growth factor-I (Igf1)	AI604642	0.74	15	1.1	ns	0.35	0.1
Igf1 binding protein 1 (Igfbp1)	AI892189	1.2	n.s.	1.0	ns	0.55	0.1
PI 3′K regulatory subunit p85 beta (Pik3r1)	AA033042	0.8	n.s.	0.8	ns	0.32	0.1
serine/threonine protein kinase (Akt2)	AA437947	0.7	5.07	0.9	ns	0.58	0.1

FDR: false discovery rate (%), FDR > 10 = not significant (ns).